People unfortunately dont take the time to train their dogs properly nowadays, especially with regards food, so it is easy to slip something to a god in a bit of meat or mince.
Start from puppy stage to teach them to only eat out of their bowls , put a piece of meat or mince , raw down on the grass or in the garden , and each time the pup goes near it , punish it, it will soon learn not to touch raw meat, or any food lying on counters that is not in his bowl.
Secondly cook your pets food , cook your pets mince, dont let the dogs grow up on raw meat.
Thirdly whenever possible , lock your dogs inside the house, a burglar is less likely to try and enter a house, that has dog slobbering to tear him apart on the inside, outside dogs are too easily distracted, and at night , keep the dogs inside, a dog is a better watchdog inside than outside.
Works for me.